Speed-varying transmission.



Patented 00L 7, I902.

M. U. REEVES &. E. K. HOOD. SPEED VABYING TRANSIMSSION.

(Application filed Apr. 7, 1902.)

2 Sheets$haet I.

(No Model.)

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Patented Oct. 7, 1902.

M. 0. REEVES &. E. K. HOOD.

SPEED VAB-YING TRANSMISSION.

(Application filed. Apr. 7, 1802.;

2 Sheets-Sheet 2.

(No Model.)

, %/.////wid RI I LIJVENTo s \AATNESS f wAsmNnTou u c barren STATES PATENT OFFICE.

MILTON O. REEVES AND ERNEST K. IIOOD, OE COLUMBUS, INDIANA, AS-

SIGNORS TO REEVES PULLEY COMPANY, OF COLUMBUS, INDIANA, A

CORPORATION OF INDIANA.

SPEED-VARYING TRANSMISSION.

SPECIFICATION forming part 01'; Letters Patent No. 710,714, dated October 7, 1902.

Application filed April 7, 1902. Serial No. 101,768. (No model.)

To all whmn it 727,07 concern:

lie it known that we, MILTON O. REEVES and ERNEST K. H001), citizens of the United States of America, residing at Columbus, in the county of Bartholomew and State of Indiana, have invented certain new and useful Improvements in VariableSpeed Devices, of which the following is a specification.

The objects of our invention are to provide a device in which the speed of a machine belted thereto may be varied while the source of power remains at a constant speed, to provide a device in which said variation can be accomplished without stopping the shaft or machine, and to provide means for maintaining an approximately uniform tension upon the belt in the mechanism hereinafter described, and, further, to provide a compact and efficient device.

The elementary construction of the device to which the present invention appertains is shown in Letters Patent No. 583,402, issued to the Reeves Pulley Company May 25,1897; Letters Patent No. 588,354, issued to the Reeves Pulley Company August 1-7, 1897, and Letters Patent No. (330,407, issued to the Reeves Pulley Company August 8, 1899.

The device described herein consists, primarily, of two parallel shafts mounted in a frame, each shaft carrying a pair of coneshaped driving elements splined thereto and having their cone-surfaces facing each other. The driving elements are provided with projecting hubs, each of which bears against a ball thrust-collar. The corresponding collars of each pair are connected by levers pivoted between the shafts and adapted to oscillate on said pivot and move one pair of disks toward each other and simultaneously therewith move the otherpair apart. A beveledged driving-belt of any desired construction, such as that shown in Patent No. 581,770, issued to the Reeves Pulley Company May 4, 1897, is stretched between the driving elements, and as one pair moves together the belt assumes a greater driving diameter, while the other pair moves apart and the belt assumes a lesser driving diameter, thus varying the speed of one shaft relatively to the other.

It is a well known principle that more belt is required to connect a large pulley and a small pulley than is required to connect two pulleys of the same diameters, the mean be tween the large and small, both being spaced equidistant. A nu mberof devices have been invented to obviate the effect of this variation in length of belt, so as to make a speedvarying mechanism of the class above described practical. Each method has its inherent ad vantages; but in our present invention we shall describe a very simple construction for accomplishing this result. I

The present invention is equally applicable to all sizes of machines, and by simply changing the proportioning of the parts any variation in belt length can be taken care of.

In the drawings, Figure 1 is a plan of our device; Fig. 2, an enlarged detail; Fig. 3, a plan of the same.

1 2 represent two parallel shafts mounted in a built-up frame 3, consisting of boxes 4, side irons 5, and cross-strips 6. All go to make a substantial rectangular frame.

Mounted on shaft 1 is a pair of cone-shaped driving elements 7, having their cone-faces toward each other and provided with projecting hubs 8, which bear against a thrust-bearing 9, preferably of the ball or rollertype. These driving elements are splined to their shaft, being free to slide longitudinally there- 0n,but compelled to rotate therewith. Mounted on shaft 2 is a similar pair of driving elements 10, provided with similar hubs and taking against thrust-bearings 11. The corresponding thrust-bearings 9 and 11 are connected by levers l2, slotted to receive bosses 13, carried by the thrust-bearings. Said levers are pivoted to an adjustable nut 14, carried by a right and left hand screw-threaded shaft 15, extended transversely across the frame and squared at its ends.

Levers 12 have extension 16 provided with slotted openings 17, taking over pins 18, carried by bell-crank levers 19, pivoted to the main frame at 20. The free end of each bellcrank lever 19 is pivotally secured to a link 21, attached at its opposite end to box 4, carrying shaft 1. The bolt-holes in boxes 4 are from shaft 2 until the levers are parallel.

slotted, so as to allow a sliding movement of the boxes toward and away from shaft 2.

When levers 12 are moved from the position shown in drawings, the boxes carrying shaft 1 are caused to recede from shaft 2, and if swung from this latter position they recede A further movement of the levers in the same direction will cause the boxes 'to again approach shaft 2. Levers 12 are extended back of shaft 2 and are provided with slotted openings 22, which take over nuts 23, carried by a right and left hand screw-threaded shaft 2%. By manipulating this screw-shaft these nuts are caused to approach or recede from each other, thereby swinging the levers on their pivots 14 and causing one pair of driv ing elements to approach each other and simultaneously therewith causing the other pair to recede from each other. As this takes place the belt'assumes a larger driving diameter upon the approaching driving elements and a smaller driving diameter upon the receding elements. Thus if one shaft is driven at a constant speed the other is varied, according to the diameter upon which the belt works. As before stated, however, more belt is required to connect the driving elements when in the position shown in the drawings than is required to connect the driving elements when they are equidistant apart and the belt is upon the mean diameter of each pair, and if no provision is made for compensating for this variation the belt would be extremely loose at its intermediate point and extremely tight when at its limit of movement. Now by noting the actionof the bell-crank levers it will be seen (referring to Fig. 1 of the drawings) that as the driving elements on the shaft 1 are receding those on shaft 2 are caused to approach each other. The bell-cranklevers force boxes 4 away from shaft 2, thus increasing the distance between shafts, and bya proper proportionment of parts this increased distance can be madejustenough to maintainthebelt at a uniform tension until the levers are parallel and the belt is upon the same driving diameter of each pair. Now by a continued movement in the same direction the bell-crank swings past the center line and the boxes are drawn closer to shaft 2, thereby maintaining a uniform tension upon the belt throughout its entiremovement. Itwillbereadilyseenthatthis action is automatic in both directions and that it is controlled entirely by the movement of the levers. There are several analogous methods of accomplishing this same result, and we consider ourselves the first to provide means for approaching the shafts toward each other and receding the shafts away from each other automatically. One analogous method consists in mounting the shafts in eccentric boxes, said eccentric boxes being controlled by the movement of the levers, and we do not, therefore, wish to confine ourselves to the specific methods shown.

What we claim, and desire to secure by Letters Patent, is-- 1. In aspeed-varying mechanism, the combination of a frame; two parallel shafts mounted therein; a pair ofcone-shaped driving elements carried by each shaft; the individual members adapted to slide toward or away from each other on their respective shafts; abelt connecting the pairs; means for simultaneously sliding the driving elements toward or away from each other upon their respective shafts; and means for moving one pair of elements toward or away from the other pair; said latter means controlled by the means for sliding the elements on their shafts, substantially as and for the purpose set forth.

2. In a speed-varying mechanism, the combination of a frame, two parallel shafts mounted therein, a pair of cone-shaped driving elements carried by each shaft, the individual members of each pair adapted to slide toward or away from each other upon their respective shafts, a belt connecting the pairs, levers pivoted between the shafts and connected with the driving elements, so as to simultaneously slide one pair toward each other and the other pair apart, means for moving one shaft toward or away from the other, said means controlled by the levers, substantially as and for the purpose set forth.

3. In a speed-varying mechanism, the combination of a frame, two parallel shafts mounted therein, a pair of cone-shaped driving elements carried by each shaft, the individual members of each pair adapted to slide toward or away from each other upon their respective shafts, a belt connecting the pairs, levers pivoted between the shafts and connected with the driving elements so as to simultaneously slide one pair together and the other pair apart, a projection on each of said levers, bell-crank levers pivotally connected with said first-named levers, and links pivotally connected to said bell-crank levers and to the boxes carrying one of the shafts, substantially as and for the purpose set forth.

MILTOL O. REEVES. ERNEST K. HOOD. Witnesses:

H. O. REEVES, J NO. J EWELL. 

